Test tube carrier

ABSTRACT

The invention relates to a test tube carrier ( 4 ) for transporting test tubes in a transport system, said carrier ( 4 ) comprising a base ( 8 ) having a recess made thereto for accommodating the bottom of a test tube/vial ( 1 ), and support members ( 9, 10 ) adapted to the carrier base ( 8 ) for clamping a test tube ( 1 ) inserted in said recess and supporting the same. The support members ( 9, 10 ) are permanently affixed to said carrier base ( 8 ) and comprise elongated portions with their free ends bent toward the vertical center axis of the carrier base and said upper ends providing a support surface ( 22 ) for making supportive contact to the test tube. The bottom of the carrier base recess for accommodating a test tube is advantageously made flat and the carrier base is provided with test tube support members whose support surfaces ( 22 ) extend to at least two different heights from the top level of the carrier base ( 8 ).

This application is the national phase under 35 U.S.C. § 371 of PCTInternational Application No. PCT/FI02/00287 which has an Internationalfiling date of Apr. 3, 2002, which designated the United States ofAmerica.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a test tube carrier according to the preambleof claim 1 for transporting different kinds of test tubes in sampleanalysis systems and other kinds of automatic specimen handling systems,wherein individual test tubes/vials are moved between separate stations.

2. Description of Background Art

These kinds of test tube carriers are conventionally used fortransporting samples to be analyzed for probing at different analyzerstations. The sample transport system comprises a conveyor lane formoving the transport carriers and a number of carrier handling points,wherein the carrier with its test tube(s) can be moved to a sampleprobing point, a queue thereof or to a buffer station, for instance. Thetest tube carrier is provided with grooves and projections thatsupportingly mate the edges of the transport track so as to guide thetravel of the carrier and secure its upright position. The travel of thetest tubes is controlled by means of a bar code attached to the tubes,whereby the bar code must be readable at all handling stationsirrespective of the tube and carrier positions.

A test tube carrier of the above-described kind is disclosed in CanadianPatent Application No. 2,216,052 related to a specimen transport system.The test tube carrier described in the publication has a central recessmade to the round carrier base having thereabout adapted retainermembers of thin, round steel wires that project upright from the base atthe sides of the recess. The bottom end of a test tube is placed in therecess, whereby the steel-wire retainer members support the test tubefrom its sides. The lower end of the steel-wire retainer memberssupporting the test tube is bent in a Z-shape so that one end of thebent wire is inserted into a hole made in the carrier base, while theother end forms an upright oriented portion that supports the test tube.The lower end of the steel wire inserted in the hole of the carrier baseis adapted freely rotatable in the hole and the upright-oriented portionof the wire is adapted in an arcuate control groove that guides themovement of the wire. The carrier base generally supports threesteel-wire retainer members that are displaced symmetrically about therecess of the base. Below the tips of the upright-oriented portions ofthe steel-wire retainer members is adapted an O-ring serving to squeezethe wires toward the vertical center axis of the carrier base so thatthe wires are forced to follow the arcuate shape of the control groovewhile their lower ends rotate in the holes of the carrier base. When thetest tube is inserted in the carrier, the steel-wire retainer membersare urged apart from each other, and, having the test tube in place onthe carrier, the O-ring clamps the steel-wire retainer members againstthe test tube.

The above-kind of test tube carrier, however, is hampered by pluraldisadvantages. Due to incorporating loosely moving members,difficult-to-clean recesses that may accumulate sample material andother impurities are formed, e.g., in the holes and control grooves ofthe steel-wire retainer members of the carrier base. As a result, thestructure has a higher need for aggressive washing and disinfection,whereby the washing step becomes extremely arduous especially for theO-ring that must be replaced from time to time due to aging. If thecompressive force exerted by the ring is lost or the ring breaks up, thetest tubes will not stay upright at all on the test tube carrier. If thetest tube flips aside during transport, the moving carriers contaminatethe transport system over a large area, whereby a long shutdown isnecessary for cleaning. Hence, the condition of the carriers must becontinuously monitored during the operation of the transport system. Themachining of the drilled holes and arcuate control grooves need twocutting steps per each steel-wire retainer member and, furthermore, anunnecessarily complicated casting mold for making the carrier base. Theuse of elongated steel-wire retainer members adapted to conform with theexterior surface of a test tube is also hampered by the problem of thewire members supporting the test tube only at one point unless the wiremembers are made extremely flexible. These support points do not readilycoincide with each other at the same height of the test tube, wherebythe test tube assumes a tipped position under the forces imposed theretoat the support points located at different heights. This problem can beovercome by shaping a conical or concave bottom for the recess drilledto the carrier base, whereby the shape of the recess bottom supportssufficiently the bottom end of the test tube with the penalty of havingtest tubes of the different size placed at different heights and makingsample recovery and reading of identification information moredifficult. If the retainer members are made from a material of such ahigh elasticity that the compressive force imposed by the O-ring canpress them along their entire length against the exterior surface of thetest tube, the wires generally become so thin that the risk of damagethereto in the insertion and removal of test tubes becomes substantial.Inasmuch the lower ends of the steel-wire retainer members and theirdrilled support holes must be located close to the periphery of thecarrier base, the base must be made high, because the transport systemguide grooves of base cannot be located within the portion of thecarrier base occupied by the holes drilled for the retainer members. Asa result, the transport system guide grooves of the carrier base must bemade to the bottom portion of the base, wherein they give inferiorguidance to the travel of the test tube carrier than if the guidegrooves were located at a higher elevation from the bottom portion ofthe test tube carrier.

SUMMARY AND OBJECTS OF THE INVENTION

It is an object of the present invention to provide a test tube carrierfeaturing secure support to test tubes inserted into a predeterminedposition and having no loosely moving members.

The goal of the invention is achieved by way of adapting in a fixedfashion to the sides of the carrier base recess such elastic membersthat offer a support surface for a test tube inserted therebetween.

According to a preferred embodiment of the invention, the test tubecarrier has made thereto a flat-bottom recess for accommodating a testtube and there are two elastic members adapted above one another so thattheir support surfaces are located at different levels from the carrierbase.

The invention offers significant benefits.

A test tube carrier according to the invention has no loosely movingparts, whereby its wear in use and need for maintenance are minimal. Asthe structure has no loosely moving parts, it can be designed free fromany recesses or holes capable of accumulating contaminating material.Accordingly, the test tube carrier is easy to clean and keep in ahygienic condition. The test tube carrier operates problem-free at alltimes and possible damage in its structure is instantly visible. Thebase part of the test tube carrier can be manufactured advantageously byinjection molding without any need for post-machining, and the device isextremely simple to produce by manual techniques or in automaticassembly systems. The test tube carrier operates reliably over a largerange of test tube/vial sizes and the bottom of the recess made in thebase part thereof for supporting the test tube bottom can be flat,whereby the test tube/vial will assume at all times an equal height anda correct alignment guided by the elastic support members. The elasticsupport members can be advantageously made from spring steel band,whereby they become sufficiently stiff for holding test tubes in areliable fashion. The location of the elastic support members does notcurtail the degree of freedom in the shaping of the exterior surface ofthe carrier base part thus allowing the guide grooves to be made deeperin order to reduce the swaying of the carrier during its travel. Theelastic support members cope with test tubes of varying dimensions andshapes as allowed within their manufacturing tolerances so as to keepthe test tubes firmly gripped by the elastic support members.

Further scope applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and of the scope of the invention willbecome apparent to those skilled in the art from this detaileddescription.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

In the following, the invention will be examined in greater detail withthe help of exemplary embodiments illustrated in the appended drawingsin which

FIG. 1 shows a test tube carrier according to the invention in itsoperating environment;

FIG. 2 shows a perspective view of the embodiment of FIG. 1; and

FIG. 3 shows a cross-sectional view of the embodiment of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, therein is shown a portion of a transport systemsuited for moving test tubes 1 placed on test tube carriers 4 betweendifferent handling stations. The transport system comprises a guide lane3 forming a transport path for the test tube carriers 4 and having rails2 at its sides for supporting the test tube carriers during their traveland preventing the same from tipping aside. At the bottom of the guidelane 3 are provided running belts 5 (not shown) on which the test tubecarriers move supportedly. The guide lane 3 forming the transport pathcontrols the transport route of a given test tube carrier 4. Operatingalong the path of the guide lane are adapted handling stations capableof performing analysis of a sample contained in a test tube,rearrangement of the sample sequence and other possible functions suchas derouting to a crossing lane. In the transport system of FIG. 1, thehandling station shown therein includes a turnstile disc 7 with atransfer slot 6 for receiving a test tube carrier 4. The test tubecarrier 4 has a rotation-symmetric shape that mates with the compatibleshape of the transfer slot. When a test tube carrier 4 comes to thehandling station, the carrier meets a transfer slot 6, whereby it can bepicked off from the lane by means of rotating the disc 7 to an analyzerfor instance. Simultaneously, the solid periphery of disc 7 preventssuccessive test tube carriers from passing forward during the time thetransfer slot is rotated off from lane 3. As the function and structureof the transport system is not essentially related to the presentinvention, its detailed description need not be discussed furtherherein.

In FIGS. 2 and 3 is shown an embodiment of the test tube carrier 4according to the invention. This kind of test tube carrier is intendedfor use in conjunction with test tubes of dia. 10 to 17 mm. The testtube carrier comprises a base 8 with elastic support members 9, 10affixed to the base. The base 8 has a rotation-symmetric shape and hasits lower portion and upper portion provided with glide faces 11, 12adapted to supportedly mate with the edges of the transport system guidelane 3. Above the lower glide face 11 is located a guide groove 13 thatmates with the shape of the guide rails 2 of transport system guide lane3. Above the guide groove 13 is first made a narrow face 14 for opticindicia and then above the narrow face 14 is located an upper glide face12. Obviously, the exterior design of a test tube carrier according tothe invention is not limited by the exemplary embodiment describedherein, but rather, the actual contour of the test tube carrier must bemade compatible with the structure of the transport lane. The base 8 ofthe test tube carrier is formed by two parts, namely, an outer shell 14and a cup part 15 adapted to fit therein. The bore of the outer shell ismachined to so as have a recess whose interior diameter is smaller thatthe inner rim portion of the outer shell 14 extending to the top levelof the outer shell 14, whereby a shoulder 16 is formed into the outershell bore. The outer rim of the cup part 15 is made compatible withthis shape of the outer shell bore so that the cup part has a larger rimportion 17 fitting snugly in the large-diameter portion of the outershell bore. The center recess bore of the cup part 15 has a straightcylindrical inner wall with a flat bottom. In a ready-assembled testtube carrier, these two parts are put together concentrically so thattheir top rims are in the same plane. In practice, these parts can bemade from polymer materials by injection molding, for instance. Since,the test tube carrier is not subjected to major mechanical stress, itmay also be fabricated from any other easy-to-clean material.

In a side view, the elastic support members 9, 10 resemble the shape ofa fishing hook. Typically, the support members are made from stainlesssteel band or any similar elastic and durable material. Each elasticsupport member comprises a single contoured strip having a right anglebend 18 made to its one end. To the opposite end of the member in regardto bend 18 is contoured a smooth arc so that the strip terminates at afinger portion 19 directed toward the right-angle bend 18 and at its endan inward hook tip 20 pointed toward the inside surface of the fingerportion. The convex edge of the hook tip acts as a supporting surface 22that rests against the periphery of an inserted test tube/vial, and thisconvex edge surface is advantageously oriented in a directionperpendicular to the center axis of the test tube and the verticalcenter axis of the base, whereby it will form a point-like contact tothe round surface of the test tube periphery. The upper set 10 ofelastic support members is made longer than the lower set. The springfunction of these elastic support members 9, 10 is provided by theresilience of the long straight portion 21 between the bent portions andthe long bend of the finger portion. In this fashion the straightportion can be made longer by having the finger portion 19 bent downwardtoward the carrier base 8.

In the illustrated embodiment, the number of elastic support members 9,10 is eight, whereby they are superposed pairwise above one another intwo concentric circles at 90° spacing from each other. The superposedsupport members are placed inside one another so that the shorter member9 is innermost thus aligning the hook portions of members 9 and 10 aboveone another in the vertical direction. The outer surface of the cup part15 of the carrier base is provided with grooves suited to accommodatethe elastic support members and having at the ends of the groovesrecesses suited to accommodate the right-angle bent end 18 of theelastic support members 9, 10. In the assembly of the test tube carrier,the elastic support members 9, 10 are first inserted in the grooves ofthe cup part, whereupon the cup part 15 with its elastic support membersis pressed into the bore of the outer shell 14 to complete the assembly.The seam between the outer shell 14 and the cup part 15, as well as theroot of the elastic support members is secured with a sealant, forinstance, whereby the test tube carrier is finished free from anycrevices capable of accumulating contamination and the locking of thecarrier members to each other is assured. Resultingly, the elasticsupport members become an integral part of the test tube carrier. Duringthe assembly step, between the outer shell 14 and the cup part 15 isplaced a so-called RFID tag memory chip that can receive theidentification data of the test tube specimen over a radio-frequencylink and then provide the read-out of the data at any time so desired.

Without departing from the scope and spirit of the present invention,embodiments different from those described above may be contemplated.

For instance, the carrier body could be made from several parts, butthis option only makes its manufacture more complicated and costlier.The number of elastic support member pairs may be varied from 3 to 5, incertain applications up to 6 pairs, with the penalty that the greaternumber of elastic support members may complicate the read-out of testtube/vial identification indicia, such as a bar code, by automaticdetection means. If the bottom of the carrier base is provided with aconical or concave recess, it is feasible to use only one elasticsupport element instead of a pair of support members in each supportmember position, whereby a test tube/vial inserted in a carrier issupported by said conical recess and only one ring of the elasticsupport elements. This arrangement, however, eliminates the benefitachievable by the flat bottom of the test tube recess in the carrier.The elastic support elements need not necessarily be placed interposedwith each other, but if the support members are staggered about theperiphery of the carrier base, difficulties will be encountered in thereadout of test tube indicia and assembly of the test tube carrier.Obviously, the elastic support elements do not necessarily have adownward directed hook portion, but their free ends may as well bedirected first toward the vertical center axis of the carrier base andthen upward. The hooked tip may be bent outwardly at the upper end ofthe support member or, alternatively, coiled into a ring.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope for the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

The end of the elastic support elements facing the test tube/vial isadvantageously shaped so as to provide at the contact point ahorizontally lineal support surface 22 that makes only a point-likecontact to the periphery of the test tube, whereby the support giventhereto becomes well-defined. However, this kind of a straighter supportmember lacking the hooked portion offers less elasticity with the sameband material thickness and makes the of the support member tips looksharper which may give a less user-friendly impression. While theelastic support elements are advantageously made in the above-describedfashion from a flat band material, also other continuous sections suchas tubular blanks may be contemplated as the raw material of the elasticmembers.

1. A test tube carrier for transporting test tubes in a transportsystem, said carrier comprising a base having a recess made thereto foraccommodating the bottom of a test tube/vial; and support membersadapted to the carrier base for clamping a test tube inserted in saidtest tube recess and supporting the same, said support members beingpermanently affixed to said carrier base and comprising elongatedportions with their free ends bent toward the vertical center axis ofthe carrier base and said upper ends providing a support surface formaking supportive contact to the test tube, characterized in thatwherein the support surface of said support members is arranged toextend to at least two different heights from the top level of thecarrier base and said carrier base being assembled from twoconcentrically insertable parts leaving therebetween recesses into whichthe lower ends of said support members are permanently affixed.
 2. Thetest tube carrier of claim 1, the bottom of said test tube recess isflat.
 3. The test tube carrier of any one of foregoing claims, whereinthe upper end of said support members include a hooked finger portiondirected toward the vertical center line of the carrier base and thentoward the carrier base.
 4. The test tube carrier of claim 3, whereinsaid support members are made from a flat band material.
 5. The testtube carrier of claim 3, wherein said support surface forms ahorizontally lineal contact surface aligned perpendicular to the centeraxis of the test tube.
 6. The test tube carrier of claim 4, wherein saidsupport surface forms a horizontally lineal contact surface alignedperpendicular to the center axis of the test tube.